Disordered gambling effects millions of Americans and is associated with higher rates of depression, anxiety, suicide attempts/completions, work/academic failure, criminal activity, family/relationship disruptions, comorbid substance use/dependence, eating, and personality disorders. Despite these social and health consequences associated with disordered gambling, it rarely receives sufficient attention as a significant public health concern. The proposed research project is aimed at identifying individuals currently experiencing problematic gambling and providing personalized normative feedback and/or brief advice on protective behavior strategies in order to prevent continuation and exacerbation of problems. The broad, long-term objective of this research is to reduce problematic and disordered gambling and the associated negative consequences through development of brief, effective, and low cost prevention techniques. While rates of pathological gambling have been reported as between 1-3 percent of the general adult population, college students have been characterized as an at-risk group with 9-15 percent currently experiencing some problems related to their gambling and approximately 5 percent meeting criteria for pathological gambling. In addition meeting criteria for pathological gambling are unlikely to seek treatment until years of compounding problems have caused sometimes devastating harm to their finances, relationships, and physical and mental health. The current study seeks to test the efficacy of web-based screening and immediately delivered intervention for at-risk or disordered college student gamblers. This prevention trial utilizes and tests theoretically and empirically-driven intervention components alone and in combination to evaluate efficacy of each component. The intervention components to be tested are brief advice for gambling (BA), personalized normative feedback (PNF), and the combined advice and norms (CAN) compared to an assessment control condition. At-risk/disordered gambling is operationalized as scores on the South Oaks Gambling Screen (SOGS) of 3 or above and reporting 1 or more negative consequences of gambling in the last six months on the Gambling Problem Index (GPI). Impact on gambling frequency, quantity and negative consequences, as well as mediating effects of increasing accuracy of gambling norms and specific gambling protective behaviors will be evaluated. The research will fill important knowledge gaps regarding the use of specific gambling advice and the use of normative feedback in preventing and reducing problematic gambling. The current project aims to meet the mission statement and strategic planning goals of the National Institute of Mental Health (NIMH) by focusing on the development of an innovative and cost-effective prevention program for an increasing public health issue of disordered gambling. The current project utilizes basic research to develop a valid and reliable measure of protective behavioral strategies, as well as test the efficacy of a cost-effective, web-based prevention program for a growing, at-risk, young adult population. The award would also aid in the ethical, methodological, and clinical training and development of a promising new researcher to address the growing need for cost-effective, mental health prevention and treatment service research.